Figure 7.3: Human earlobes may be free or attached. You inherited the particular shape of
your earlobes from your parents. Inherited traits are influenced by genes, which are passed
on to offspring and future generations. Your summer tan is not passed on to your offspring.
Natural selection only operates on traits like earlobe shape that have a genetic basis, not on
traits like a summer tan that are ”acquired.” ( 4 )
trading, Darwin went on land to explore and look for the local plants, animals, and fossils.
One of the most important things Darwin did was to keep a diary. He took extremely
detailed notes and drawings about everything he saw as well as his thoughts.
Figure 7.4: Charles Darwin’s famous five year voyage was aboard theHMS Beaglefrom
1831-1836. ( 7 )
The Galápagos Islands
The around the world voyage of theHMS Beaglewas mostly to map the coastline of South
America. Darwin’s best known discoveries were made on the Galápagos Islands (Figure
7.5), a group of 16 volcanic islands near the equator about 600 miles from the west coast of
South America. Darwin was able to spend months on foot exploring the islands. Darwin’s
Theory of Evolution by Natural Selection was a result of his observations and over 20 years